'Testimony': Debbie Rowe, seen last month in California, will be called to the stand by promoters AEG, it has been claimed

Michael Jackson's ex-wife Debbie Rowe will be called to the stand by AEG in his family's wrongful death case against the concert promoters AEG, it has been claimed.

Relatives of the King of Pop - who died in 2009 after overdosing on painkillers - have accused AEG Live LLC of failing to properly investigate her son's physician Dr Conrad Murray.

But according to a new report Rowe will take the stand and testify that Jackson was a 'secret, hardcore drug addict' for decades - in what could be a hugely damaging blow for his family's case.

Sources told gossip website TMZ.com Rowe, 54, who is the mother of Jackson's children Michael Prince and Paris, will say she was aware the star was abusing some prescription medication during the 1980s and '90s, but that she did not realise the extent of his habit.

Rowe will tell jurors she had been unaware Michael's dermatologist Dr Arnold Klein had 'a standing order... when Michael came to the office he should be injected with Demerol and Vistaril', TMZ said.

Vistaril increases the strength of painkiller Demerol, the report said.

It claims Rowe will say Michael hid the extent of his problem from her - testimony that would likely boost AEG's argument it had no reason to be aware of the singer's drug abuse.

It is claimed the mother-of-two will reveal how she saw Michael emerge from Klein's office looking 'out of it' in the days leading up to his death.

TMZ said she would describe a phone call she allegedly made to Klein during which she told him: 'He's dead and it's your fault'.

She will say she was unaware Jackson was visiting doctors with the specific aim of 'getting high and falling asleep', the report said.